The present disclosure relates to power loss measuring system for measuring power loss in a harmonic filter using variation in impedance of each element included in the harmonic filter, and a power losing measuring method thereof.
High Voltage Direct Current (HVDC) transmission indicates a power transmission method of converting, by a transmission site, alternative current (AC) power produced at a power station into direct current (DC) power to transmit the DC power and then re-converting, by a reception site, the DC power into the AC power to supply power. The HVDC transmission may enable efficient and economical power transmission through a voltage increase that is the advantage of AC transmission. In addition, the HVDC transmission may overcome many limitations of the Ac transmission.
In such HVDC transmission, it is essential to convert AC power into DC power and then the DC power into Ac power. However, harmonics occur due to characteristics of a switch and a load during the conversion, and therefore, a harmonic filter is generally used to prevent harmful effects of the harmonics.
A general configuration of the harmonic filter is as shown in FIG. 1.
Referring to FIG. 1, the harmonic filter includes at least one inductor, at least one capacitor, and at least one resistor.
Conventionally, to measure power loss occurring at a harmonic filter, a voltage and a current are measured in a Gas Insulated Switchgear (GIS) 10 disposed in a receiver of the harmonic filter. That is, the power loss occurring at the harmonic filter is conventionally calculated using voltage and current values measured by the receiver of the harmonic filter.
However, an existing system for measuring power loss in a harmonic filter aims mainly to measure voltage and current, rather than the power loss itself. In addition, it is hard to measure power loss according to a real-time change in temperature and frequency because variation in impedance according to a change in temperature and frequency is not known. Further, power loss of each element cannot be measured, and variation in impedance according to a change in a voltage and a current is not known, so that they cannot be reflected in the system design.